Cobra Amp Cell Pro Iron Hosel Bore Diameter

[M2R]

Recently I got a used set and trying to research the hosel bore diameter proved inconclusive. Confirmed that Amp Cell irons have universal hosel bore but no confirmation on the Pro versions. One source did report that bore was for .355 taper shafts, where others suggested that bore should be the same universal bore as on non-pro versions.

My shafts are .355 taper and the 4 iron had a non-matching ferrule to the rest of the set.  Which is why I started down this road. What I found on my 4 iron was that it most definitely was a universal bore, and one I particularly disliked. The bottom of the bore has a very short and steep tapered section for centering .355 taper shafts. However, the top of the hosel is very loose regardless of .355 or .370 shaft. My final conclusion was that the bottom is centered by that short, tapered section, where the .370 shafts become VERY tight and the top section is not centered at all UNLESS using a collared ferrule that is a tight fit into the recess on the hosel.

On a .370 shaft I would trust this gap under the collared ferrule using shafting beads. But on a .355 shaft I would not trust this rather large gap to just globing a lot of epoxy, even with shafting beads. The frustrating part is that normal .355 to .370 shims do not work well as they are to tight at the bottom and to lose at the top. My solution was to fashion some aluminum shims that sit just under the ferrule but only extended down about 3/4 inch. However, fashioning these shims was a total PITA!

So far, this experience has made me not want to consider and/or buy any further Cobra products. However, yesterday I took the 5 and 7 iron to the range and I can say that it was a more than pleasant experience, so my opinion on Cobra has been considerably mitigated by that! On the downside, the reason I did not take a 6 iron was because it is making snapping sounds and from putting it in a vise, I can tell it is from the head coming lose from the shaft. My suspicion is that the person who mangled the 4 iron job also had a hand in the 6 iron situation. The troubling part being the uncertainty of it all. I really, really do not want to have the experience of launching an iron head down the fairway along with the ball!

Finally, I have to say that the report that the Pro version is .355 taper might be correct. My set is a flow set, so potentially the muscle back only version may be .355 while my flow irons are universal, yet another unknown.